1. Field
Aspects of the present invention are generally related to medical image diagnosis apparatuses, non-destructive inspection systems, detecting apparatuses applicable to an apparatus for analyzing with radiant rays, and detecting systems.
2. Description of the Related Art
In recent years, thin-film semiconductor manufacturing has been applied to detecting apparatuses and radiant ray detecting apparatuses each including a combination of a switching device such as a thin film transistor (TFT) and a sensing element such as a photoelectric conversion element. Such a detecting apparatus or a radiant ray detecting apparatus may have a large area of 35 cm×43 cm or 43 cm×43 cm. For improved sensitivity, detecting apparatuses have been proposed which structurally include Active Pixel Sensor (APS) type pixels as disclosed in Japanese Patent Laid-Open No. 11-307756 or 2005-175418. In an APS type pixel, electric charges generated in a sensing element define a potential of a gate of a switching device for amplification. When a switching device for selection is brought into conduction, the voltage according to the potential of the gate defined by a follower operation charges a parasitic capacitance of a signal line. Thus, an electric signal amplified in accordance with an amount of the electric charges generated in the sensing element is output from the pixel to the signal line. In other words, in a detecting apparatus having APS type pixels as disclosed in Japanese Patent Laid-Open No. 11-307756 or 2005-175418, the amplification degree of or the time for outputting electric signals from the pixels depends on a parasitic capacitance of a signal line.
However, according to Japanese Patent Laid-Open No. 11-307756 or Japanese Patent Laid-Open No. 2005-175418, the value of a parasitic capacitance of a signal line may vary in accordance with the area of the detecting apparatus including them or the width of a signal line therein, which may possibly changes the amplification degree of or the time for outputting electric signals output from pixels. The amplification degree and the outputting time may be adjusted by adjusting the parasitic capacitance of a signal line irrespective of the apparatus including them through adjustment of the area of the apparatus and the width of the signal line. However, in consideration of noise that depends on the parasitic capacitance of a signal line, the parasitic capacitance of the signal line is required to be extremely low. Therefore, in a design that adjusts the parasitic capacitance of a signal line, it is not easy to keep a preferable S/N ratio and also keep a desired amplification degree of or time for outputting electric signals. Particularly in a detecting apparatus having a large area produced by thin-film semiconductor manufacturing, the parasitic capacitance of signal line may change as largely as 50 to 150 pF due to a change of the area, for example, and the parasitic capacitance of the signal line may significantly affect.